Confined Spaces: Learning and Trusting Your Gas Detector

With the proper training, personnel, and comfort with your equipment, you can mitigate many of the potential risks.

By Bryan Szczur

Aug 01, 2015

The rain fell as I stood at the top of the rappel tower; looking down at the ground, I prepared for a 50-foot descent. I had been an Army ROTC cadet for just two weeks, and this was the first time I had ever done any kind of intense physical training. The rappel master, who called the shots from the top of the tower, was a seasoned veteran who had no time for a hesitant cadet like me. A fellow cadet waited at the bottom, standing on belay as a safety precaution. The rappel master checked my gloves, helmet, rope, knots, and carabiner before giving me the go-ahead to proceed down the tower.

Prior to the actual rappelling, he'd spent several hours teaching us how to tie a Swiss seat knot, secure our carabiners, tighten our helmets, and check our gloves for any holes or tears. After we all were familiar and comfortable with our equipment, we spent another hour practicing the appropriate techniques for descending and braking while on the rope. We also practiced the proper way to secure the rope from the bottom when acting as the belay man, in the event that the soldier on rappel would lose grip and fall. Being the young, inexperienced kid that I was, all of these safety precautions seemed unnecessary. While I didn't realize it at the time, that sergeant was responsible for the safety of every cadet on that tower. Looking back on that day and all of the training events I've participated in since then, I've learned that safety must always be the top priority—no matter what trade or industry you work in.

A regard for safety is especially important for workers who encounter potentially hazardous scenarios every day. Confined space entry, for example, requires workers to take an approach similar to Army cadets: You must trust your training, trust your buddy, and trust your equipment.

Trust Your Training
The Army prepares soldiers for mission-essential tasks every day. Once soldiers complete repetitious training, their duties, responsibilities, and tasks become second nature, along with the safety procedures they follow while undergoing this training. With enough instruction and rehearsals, workers can follow the same process when having to enter a confined space.

One safety issue a worker may encounter when entering a confined space is exposure to hazardous gases. To effectively monitor these gases, workers must use gas detectors properly. For this reason, gas detection manufacturers often provide training classes to help workers gain an understanding of the basic functionality and application of their instruments. These courses offer an in-depth approach to gas detection, covering the components of the gas monitors and the intricacies of their makeup. If you don't know where to begin with your gas detector training, take a course. You will get hands-on training and perform all of the basic procedures for operation, and the best way to learn is by doing. If you are unable to take a course, some manufacturers also offer online training videos that walk you through the proper operating and maintenance of an instrument. The resources are there to help you learn your gas detector and ultimately to keep you safe.

If your manufacturer offers a confined space-specific class, it likely will begin by covering what a confined space is. By definition, a confined space is an area with limited entry and exit that is large enough for bodily entry and is not designed for continuous occupancy. Due to these conditions, confined spaces are hazardous and pose potential risks. For example, you may learn that the most common cause of death in confined spaces is oxygen deficiency, so right away you would need a monitor that can detect for low oxygen levels. You may also learn certain aspects of common toxic gases. For example, the course may cover how hydrogen sulfide is heavier than air, meaning it would likely be present at the bottom of a confined space. It may also cover how carbon monoxide (another common toxic gas) is slightly lighter than air, meaning it could be anywhere within a confined space.

These are just a few of the many examples you will go over. The class also may cover the proper way to take samples from a confined space by using a monitor with a sampling pump and tubing.

Upon completion of the class, you will be evaluated on a simulated confined space entry. Similar to the several hours of knot-tying and simulated rappels, the material and practical exercise will surely prepare a worker to enter a confined space safely and confidently. The most important thing to remember is that the training does not end with the class. It is vital that you take the information with you and train your fellow employees.

Trust Your Buddy
In the Army, a soldier never goes anywhere without his battle buddy. This decades-old safety technique is simple yet effective, and it should also be applied in confined space entry. One worker enters the space wearing a gas detector while the other stays at the entrance and continuously monitors the space with his gas detector. This not only provides a sense of redundancy to a safe entrance, but also it ensures that both workers are paying attention to the potential hazardous gases inside that space. Should something happen to the entrant, the attendant can use whatever extraction equipment there is or immediately contact the rescue crew to save the injured worker. Remember, the attendant should never enter the space without proper protection in an attempt to save the entrant if it appears that the entrant has passed out or lost consciousness.

The important takeaway is that that both the attendant and entrant should be properly trained in each other's responsibilities. This not only creates a sense of safety between the two, it can also prevent an injury or death. The entrant should know that the attendant has his back if anything were to happen, just like the soldier and his battle buddy.

Trust Your Equipment
A soldier in training needs to know not only what equipment he has, but also how to use it to his advantage. For example, two soldiers traveling in a vehicle will have a GPS system, communication devices, and a map so that they and everyone else can track where they are at all times. However, they can encounter a whole slew of issues if they don't know how to use their GPS, communicate through the radio, or read a map. These pieces are vital to training and to mission success, and soldiers heavily rely on them to accomplish their tasks.

Similarly, a gas detector is virtually useless if a worker entering a confined space does not know how to properly use it. If you don't know how to use your gas detector, how can you trust it?

When monitoring for harmful gases in a confined space, you must know the capabilities and functionality of your gas monitor. The four common steps to operating a gas detector are to turn it on and check the battery status, zero the sensors, bump test, and clear the peaks. It is one thing to tell workers to follow these steps, but it is even more important to ensure that they know how. The resources are there to help workers learn their instruments, whether it be a classroom session, a product manual, an online video, or even a phone call to a company representative.

It is also vital that workers understand their monitors' sensor configurations and why this would be relevant to the space they will enter. For example, the most common gases could be carbon monoxide, hydrogen sulfide, or a combustible gas such as methane or pentane. If any of these is present, it would lead to a displacement of oxygen. For this reason, many companies choose to monitor their spaces with a standard four-gas monitor containing these types of sensors.

Other volatile organic gases, such as acetylene or toluene, also may be present in a tank. In these instances, a standard four-gas monitor would not suffice for an accurate reading. Because of this, manufacturers offer gas monitors with a photo ionization detector, also known as a PID.

If workers are aware of the potential for gases to exist in a confined space, they should understand how to use their monitor properly to keep them safe. Only then can they trust their gas detector.

Conclusion
The bottom line for a soldier is that if he or she skips a safety precaution, his or her life and the lives of others could be at stake. This is no different for workers following the proper safety precautions before, during, and after a confined space entry. With the proper training, personnel, and comfort with your equipment, you can mitigate many of the potential risks. So whether you are a young cadet on a rappel tower or a worker going in for a day’s work, remember that safety must always come first.

This article originally appeared in the August 2015 issue of Occupational Health & Safety.